* ypuntot <ypun...@gmail.com> [2023-02-04 22:01]: > Great link! > https://spin.atomicobject.com/2016/07/06/time-zones-offsets/ > > "Given a local time and an offset, you can know UTC time, but you do > not know which time zone you’re in (because multiple timezones have > the same offset)."
Exactly. > So, given a time zone you can know the offset (Google it, for > example).. Then, given the time zone and the local time, you can > know UTC. If orgmode gets the UTC there is not ambiguity. Majority of people do not use UTC. Having time displayed in UTC would and will confuse too many people, unless such time is only for logging purposes. But Org timestamps like DEADLINE, SCHEDULE, are really meant for a human. Internally, in calculations, program shoulde find time time zone, UTC offset, calculate, go to UTC, again to time zone, and again represent proper time. And if not that way, in any case there is complexity involved. Here is also good reference telling people how to program and work with time zones. Working with Time Zones: https://www.w3.org/TR/timezone/ > But, that would mean that the offset related to the different time > zones must be downloaded and updated from some site. For past timestamsp, one could store such as UTC time, and such time may be easily represented in presen time, it may be viewable in local time if computer program consults the time zone database. For timestamps we are making now, to record something, when it happened, we could use UTC time, but only for logs and similar, not so important time representations, which we will not revisit too often in future. But let us say for some future, timestamps in DEADLINE, SCHEDULED, those timestamps related to human, the UTC offset in this case cannot be so sure, because it is in the future, and it is vague as it could change politically. So the future will know what will be the UTC offset. > As you said before, that offset can change. For example, peninsular > Spain has the same time as Berlin, but as this doesn't make much > sense, it could change, so updates would be necessary. That is right. Even the time zone designation (name) could change in future, but for that reason, if we use today a time zone, the future time zone database will know about time zone that (was) defined today, and computer program will know how to calculate representation of the time in local time in future, for the time of today. Time zones are updated regularly, but we cannot be sure of it in case of atomic war or other planetary commotions. ☹️ I wish people could love each other more. ☮️ -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns In support of Richard M. Stallman https://stallmansupport.org/
